Method for corrugating and compressing flexible tubing



3, 1968 T. w. MARTINEK I 3,397,264

METHOD FOR CORRUGATING AND COMPRESSING FLEXIBLE TUBING Original FiledJuly 24, 1964 3 Sheets-Sheet 1 J L 'IIIII IIII/IAiiiiM 9 2o Jim-1.9

INVENTOR. 77/0/1445 /44 MAAT/A EK 1968 T. w. MARTINEK 3,397,264

METHOD FOR CORRUGATING AND COMPRESSING FLEXIBLE TUBING Original FiledJuly 24, 1964 3 Sheets-sheet 2 l NVENTOR.

7790/1145 M MMT/A EK Aug. 13, 1968 w, -rm 3,397,264

METHOD FOR CORRUGATING AND COMPRESSING FLEXIBLE TUBING Original FiledJuly 24, 1964 5 Sheets-Sheet 3 Fig; 5 20 INVENTOR. THOMAS m MART/NEK i31MP A 7 TORNEY.

United States Patent 3,397,264 METHOD FOR CORRUGATING AND COMPRESSINGFLEXIBLE TUBING Thomas W. Martinek, Crystal Lake, 111., assignor, by

mesne assignments, to Union Oil Company of California, Los Angeles,Calif., a corporation of California Original application July 24, 1964,Ser. No. 384,974, now Patent No. 3,343,220, dated Sept. 26, 1967.Divided and this application Apr. 21, 1967, Ser. No. 656,966

1 Claim. (Cl. 264-287) ABSTRACT OF THE DISCLOSURE The method embodiescorrugating and compressing flexible tubing. A ferromagnetic material issuspended Within flexible tubing. As oscillating motion is imparted withmagnetic force to the ferro-magnet which then moves between a first andsecond point. After the tubing is peripherally depressed theferro-magnet creases, then corrugates the walls of the tubing and movesthe corrugated segments into compression.

This is a division of application Ser. No. 384.974, filed July 24, 1964,now US. Patent No. 3,343,220, granted Sept. 26, 1967.

This invention is directed to a method of suspending and/or oscillatinga member in space by magnetic and electro-magnetic forces.

This invention also relates to the art of performing operations on andtreating the walls of flexible continuous tubing. More particularly,this invention relates to a method wherein flexible tubing is corrugatedand compressed in one operation. The invention is Sl'lOWn as applied toextruded plastic tubing in which the tubing is corrugated or shirred andcompressed in one apparatus. However, the invention is not to be limitedto a shirring operation nor is it to be limited to operations performedon plastic tubing. For instance, rather than corrugating or shirring,the tubing could be imprinted, perforated, embossed, etc. This inventionis applicable to other types of tubing such as is used in the sausagecasing industry wherein the tubing is referred to as a casing and isusually made from the intestinal linings of animals. Throughout thisspecification the term tubing shall be taken to mean edible and inediblesynthetic and naturally occurring organic material from which sausagecasings can be formed as well as tubing used for other purposes.

The sausage industry has in recent years utilized inedible syntheticcasings in which to prepare sausage meats. The development of thesynthetic continuous casing has made it necessary to resort to somemeans of compacting the extruded casing so that filling, storage and/ortransit of the casing could be facilitated. In developing a techniquewhich would ease the handling, filling and storage of the extrudedcasing the sausage industry has resorted to corrugating the casing andthen thereafter compacting or compressing the tubing into easily storedpackages and have thus been successful in easing storage, handling andtransportation problems. However, in corrugating the casings the presentstate of the art requires specialty gears working around a mandrel andagainst air pressure to pleat or corrugate the casing and thereaftercompressing the pleated tubing in a separate operation so that thecompressed casing occupies much less space than it would if the casinghad not been pleated and compressed. This method while practical has notproved to be entirely satisfactory. Perforation or puncture of thecasings caused by the specialty gears working around the mandrels hasresulted in a great monetary loss to the casing manufacturers and meatpackers. Of course. if the casing is mp tured the sausage meat cannot beblown or stuffed into the punctured casings and this problem hasnecessitated Work stoppage in the filling of the sausage casing toeither repair or cut out the damaged portion of the casing used in thecontinuous sausage meat filling apparatus. It has been estimated thatmany thousands of dollars have been lost annually due to the inadvertentpuncturing of the casings as they are being corrugated and the resultantwork stoppage that occurs when the punctured portion of the casing isfed into the sausage meat filling machine. This invention thereforeprovides a method which is substantially superior to the prior artmethod used in the industry for pleating, corrugating or otherwiseperforming operations on flexible tubing the like.

An object of this invention is to provide a method for suspending and/orcontrolling the movement of a visibly unsupported object in space.

An object of this invention is to provide an eflicient, quick andeconomical method for corrugating, pleating, embossing, imprinting andotherwise performing operations on the walls of flexible, substantiallynon-elastic tubing.

Another object of this invention is to provide a method whereby the thinwalls of substantially non-elastic flexible tubing are shirred andcompressed simultaneously.

These and other objects will be readily apparent from the followingdescription and drawings'in which:

FIGURE 1 is a side elevation, cross-sectional view illustrating onedevice that may be employed in accordance with the present invention;

FIGURES 1A and 1B are cross-sectional views illustrating the operationand use of the device of FIGURE 1.

FIGURE 2 is a front view of a further modification of an alternateembodiment of this invention on line 22 of FIGURE 3;

FIGURE 3 is a side elevation, cross-sectional view of the apparatusillustrated in FIGURE 2;

FIGURE 4 is a side elevation, cross-sectional view of another embodimentof the apparatus; and

FIGURE 5 is a side elevation, cross-sectional view of still anotherembodiment of the apparatus.

The invention will be more readily understood by reference to theaccompanying drawings in which like numerals of reference designatecorresponding components in each of the several figures.

Referring to FIGURE 1, the numeral 1 represents an electromagneticallyoperated tu bing corrugator. A guide means 2, depicted here as anannular, hollow, elongated conduit, is fashioned from a non-magneticmaterial such as brass, aluminum or plastic and is of a diametersufficient in size to allow the free passage of the flexible tubing tobe plated or shirred therethrough. For example, if the flexible tubinghas a normal diameter of 1 inch, the interior diameter of the conduitcan be about 1.0051.100 inches. The wall thickness of the guide means 2is preferably small, say less than 0.125" so that the generation ofmagnetic flux adjacent the interior wall may be efiiciently utilized. Aseries of apertures 4 are spaced circumferentially around guide means 2.The number and size of the apertures 4 may be such that a continuousslit is formed. The internal diameter of the guide means 2 posterior toapertures 4 is of slightly less diameter than the anterior portion ofthe guide means such that frictional forces will act upon the flexibletubing beginning at =projection 6 of the posterior portion of guidemeans 2. Ferromagnetic hammer 8 is positioned within guide means 2 andis fashioned of ferrites or a metal such as iron, steel, cobalt, nickel,an iron-nickel alloy composed of nickel and 20% iron or aniron-aluminum-co balt alloy marketed under the trade name Alnico.Secured to the posterior surface of hammer 8 is a second guide means 10which extends into the posterior passage formed by guide means 2. Guidemeans is preferably a non-magnetic material and preferably issubstantially coextensive with the posterior portion of guide means 2.Guide means 10 may be either an integral part of hammer 8 or may be ashaft inserted in hammer 8 in such a manner that hammer 8 is free tomove laterally on shaft 10 within certain limits, thus makingoscillatory motion of guide shaft 10 unnecessary. Hammer 8 is freelymovable within passageway 12 and is of smaller cross-section than guidemeans 2 in order to provide an annular passageway 14. A plurality ofwire windings forming central coil 18 are disposed on the exteriorsurface of guide means 2 circumferential'ly encompassing hammer 8. Themagnetic force of central coil 18 when energized is sufiicient to causehammer 8 to assume a position in the middle of the anterior region ofguide means 2. Wire windings comprising coils 16 and 17 disposed on bothsides of coil 18, upon alternate energization and de-energization, causehammer 8 to oscillate in an axial manner to and away from apertures 4.Conduit supplies air or other inert gas under pressure to chamber 22where the gas is ejected through apertures 4 against the exteriorsurface of the tubing. Air or gas chamber 22 is preferably fashioned ofnon-magnetic material so as not to impose attractive or repulsive forcesupon hammer 8.

The operation of the device of FIGURE 1 is best described by referenceto FIGURES 1A and 1B. For simplicity the guide means here is shown ascomprising anterior section 2 and posterior section 60, having aninterior diameter slightly less than the interior diameter of member 2.As an alternative embodiment projection 6 is shown as a friction fitring insert within member 60 for reasons which will hereinafter becomeapparent. Chambers 22 and guide means 2 and 60 are secured in place bymeans not shown. Referring to FIGURE 1A, hammer 8 is mounted in startingblock 9 with guide means 10 fitted into bearing surface 11 machined inblock 9. Flexible tubing 3 is slipped over hammer 8 and stretched overthe surface of block 9 so that hammer 8 is free to move with respect totubing 3 but the block 9 is not free to so move. The assembly hammer 8,block 9 and tubing 3 is inserted into the device of FIGURE 1 so thatblock 9 is friction fit to the posterior region. Coil 17 is energizedpulling hammer 8 back to the position illustrated in FIGURE 1A. Inertgas is admitted under pressure to chamber 22 where it is ejected at highvelocity against the flexible tubing 3, causing the tubing to bedepressed in the region of the apertures 4 as shown in FIGURE 1A. Coils16 and 17 are alternately energized and de-energized causing hammer 8 tocompress the depressed region of tubing 3 and advance the pleated andcompressed tubing into the posterior region ejecting the starting block9 from the posterior region.

Referring to FIGURE 18, the relative positions of the cooperating partsduring a compression cycle are shown. It may be seen that the hammer 8has moved the depressed tube section well into the posterior regionforming a series of compressed folds 13 within the friction fit guide 60forming a section of shirred tubing having exact dimensions. Activationof coil 17 causes the hammer 8 to return to the position illustrated inFIGURE 1A. The shirred and compressed tubing remains in position becauseof the projection 6 and the friction between guide 60 and the tubingfolds. The air jet causes collapse of the tubing and alternateactivation of coils 16 and 17 causes repetition of the cycle.

Referring to FIGURES 2 and 3, guide 2 fashioned of non-magnetic materialhas recessed within its interior wall thereof two permanent magnets withthe magnetic lines of force extending from surface 32 to surface 34. Thepolarity of surfaces 34 are identical, creating repulsive lines ofmagnetic force between annular magnets 30. Hammer 8" comprises permanentannular magnets 52 at the extreme ends of hammer 8" with ferrite disc 56comprising the center portion of hammer 8" and being separated frompermanent magnets 52 by non-magnetic material 58. Shaft 10 is fastenedto the posterior face of hammer 8 by, for example, spot welds or brazingand extends into second guide member 60 fashioned from non-magneticmaterial. In this embodiment the lines of force between the permanentmagnets 30 comprising part of the guide 2 and the lines of force of thepermanent magnets 52 comprising hammer 8" are equal and opposite andcoact to suspend hammer 8" within guide 2. The magnetic properties ofthese novel magnets as well as their mode of manufacture are describedin US. Patent 2,828,264, incorporated herein by reference. Theenergization and de-energization of windings 16 create magnetic forcesacting upon ferrite disc 56 causing hammer 8" to oscillate in an axialmanner between apertures 4 of air chamber 22 and the anterior portion ofpassage 12 formed by guide means 2. Members 2, 22, and 60 are secured toeach other by conventional means not shown, to prohibit relativemovement between members.

FIGURE 4 illustrates an alternative embodiment of the apparatus depictedin FIGURE 3 wherein wire windings 16 are replaced by slidable permanentmagnets 70 which are disposed on the outer surface of guide 2 which uponmovement of rod 72 causes permanent magnets 70 to slide on the exteriorsurface of guide 2 by means of lubricated bearings 74 which movementimposes magnetic forces upon ferrite disc 56 causing hammer 8" tooscillate in unison with the movement of magnets 70.

Referring to FIGURE 5, there is depicted an apparatus which uses onlyone coil for activation of the oscillation cycle wherein resilient meansor spring action along with inertial and reactive forces complete thereturn cycle of the hammer means 8". Hammer means 8" comprisesferromagnetic section 76, having a configuration suitably shaped toreadily receive the tubing which is to be shirred and compressed,secured to section 78, which may or may not be ferromagnetic, by meansof threads 80. Section 78 has recessed slot 82 adapted to receiveresilient means or coil spring 84, which spring upon compression issufficient in size and strength to impart suliicient intertia to themass to move sections 76 and 78 to the precompre'ssion position uponrelease of the compressive forces. Section 78 is machined to form aclose fit with striking-end section 96 so that sections 78 and 86 coactin a piston and cylinder like manner when spring 84 is compressed.Projection 88 of striking-end section 86 works against coil spring 84within recess slot 82 tending to maintain maximum displacement ofsection 86 with respect to section 78. Section 76 is provided withpassageway 90 of sufiicient diameter to receive head 92 of shaft 10'.Shaft 10' passes through passageway 93 of section 78 and slidably bearsagainst the interior surfaces of passageway 93 and thencely passesthrough passageway 94 of striking-end section 86 and extends into guide60 where it is supported by a fulcrum means, not shown, which maycomprise the corrugated tubing itself or other mechanical equivalentswell known in the art. It can be seen that shaft '10" centrally supportshammer means 8" within, but out of contact with the interior walls ofguide means 2. Projection 96 of striking-end 86 and projection 98 ofsection 78 have lips 100 which mate and prevent coil spring 84 fromseparating section 78 and striking-end 86 but which permit movementbetween sections 86 and 78 within preset limits. The mode of operationof this apparatus is essentially the same as herein before describedwith the exception that hammer means 8" is movable with respect to shaft10' which remains substantially immobile. In addition only one electriccoil 102 is utilized which upon energization by a source of flashcurrent draws sections 76 and 78 into striking-end section 86compressing spring 84 and moving striking-end section 86 towardsorifices or apertures 4 where the tubing is shirred. Uponde-energization of the coil 102, spring 84 returns hammer means 8" byinertial forces to the starting position for recycle.

The electrical circuitry necessary for the operation of the describedapparatus is well known in the art and will not be described in detailinasmuch as specific adaptations will inherently depend on the masses ofthe components utilized, the operations to be performed and otherengineering matters necessary to produce the balance of forcesnecessitated by the foregoing considerations.

Generally, it is preferred that the source of flash current, provided tothe wire windings comprising the coils, be one which provides anexceedingly brief impulse or current. For example, it might use a halfcycle of current derived from an oscillatory circuit. In other instancesa larger cycle may be necessitated depending upon the operation to beperformed and the path length of the inner member, comprising the hammermeans, within the outer member comprising the guide means of the variousapparatus. Likewise the number of turns of wire comprising the coils andmagnitude of the cur-rent supplied thereto will be similarly affected.

While the invention has been described in several various embodiments,it is to be noted that similar configurations following the principlesas herein set forth will serve equally as well. The sizes of the magnetsused in the various embodiments of this invention are matters which arewell within the skill of one in the art and will not be discussed atlength, it being only important that they be of suflicient size and inproper position to produce the required end results, that is,magnetically suspend the hammer within the guide and/ or oscillate thehammer. The hammer may be a solid member or a hollow member, the choiceof construction depending upon the modes utilized to suspend and/ oroscillate the hammer and the operating characteristics desired. Forinstance, in the embodiment depicted in FIGURE 1, wherein several setsof electrical windings are utilized to impart oscillating movement, thesame end result can be expected when using a hollow hammer member orwhen employing only two or additional sets of wire windings.

Although specific examples have been confined to the use of a hammercylindrical in shape, other configurations would sufiice equally aswell. Ideally, the anterior portion of the hammer should be of smallerdiameter than the posterior end to more readily permit the passage ofthe flexible tubing therearound. The shaft secured to the end of thehammer can be looked upon not only as a support means for the hammer butalso as a means to prohibit complete deformation of the flexible tubingby the air jets and also as a means of keeping the corrugations separateand distinct thereby prohibiting interlocking and disruption of thecontinuity in the corrugations. The hammer means or inner member mayalso be coated with a material, such as for example plastic, to reducethe amount of friction between the movable components of the apparatus.

While the apparatus has been described as a sausage casing corrugator,it is not to be thusly limited as it is readily apparent that theapparatus can perform other functions such as embossing, imprinting,perforating, cutting, etc. It is readily apparent that the device iswell suited for performing two operations in one, i.e., corrugating andcompressing exible tubing wherein the number of punctures or ruptures isdrastically reduced. The device is superior to other prior art devicesinasmuch as there are essentially no bearing surfaces except that of theplastic tubing and due to the small number of moving parts, thesapparatus requires little or no maintenance.

I claim:

1. A method of corru-gating and compressing flexible tubing whichcomprises the steps of (1) suspending a ferromagnetic member within saidtubing; (2) imparting an oscillating motion to said suspended memberwhereby said member oscillates between a first and second point; (3)peripherally depressing the tubing at the second of said points as saidmember moves towards said second point whereby the end surface of saidsuspended member strikes the walls of said tubing thereby creasing thewalls of said tubing in corrugated form; and (4) limiting the travel ofthe tubing past the point of corrugation whereby the corrugated tubingis compressed.

No references cited.

ROBERT F. WHITE, Primary Examiner.

R. R. KUCIA, Assistant Examiner.

